The loudspeaker module is an important acoustical component of the portable electronic device, is used for transforming electrical signal and acoustical signal, and is an energy converter. The existing loudspeaker module typically comprises a module housing in which a loudspeaker unit is accommodated, and the inner cavity of the entire module is divided into a front acoustic cavity and a rear acoustic cavity by the loudspeaker unit. The existing loudspeaker unit is typically positioned by a positioning structure provided on the module housing, and then fixed on the module housing by gluing. Such a module with a positioning structure provided on the module housing for fixing the loudspeaker unit has the following drawbacks: the structure of the module housing is very complex, the processing of the module housing is difficult, and the positioning structure will occupy the space of the inner cavity of the module, which will seriously affect the acoustic performance of the module. At the same time, the gluing process is complex, the fixation is not firm and the sealant is prone to cracking, which seriously reduces the service life of the module.
As the current portable electronic devices are becoming lighter and thinner, the structure of the loudspeaker module is required to be adapted to the change in the internal space of electronic equipments. In order to ensure the acoustic performance of the module, that is, to ensure that the space in the inner cavity of the module is large enough, the structures of the loudspeaker modules are mostly irregular structures, and some of the loudspeaker units within the modules will be infinitely close to the edge of the module housing, and even parts of some loudspeaker units will be exposed to the outside of the module housing. The inner cavity of such a loudspeaker module with exposed parts of loudspeaker units is more difficult to be sealed. At present, the commonly used solution is to apply a great quantity of sealant between the loudspeaker unit and the module housing. However, this kind of sealing method not only has difficult assembly process, high complexity, and high production cost, but also has poor airtightness, low quality of appearance and low product yield.